Update June 12, 2021 Moorea, FP
12 June 2021
So, as I mentioned in the previous post, we were planning on upgrading our batteries to Lithium. Well, the batteries arrived by Ocean shipping as well as a few other items to mount the new 340-watt solar panels. We headed over to the "working dock" at Marina Taina (our home most of last year...) and the new batteries were delivered to the boat around 1 PM. After loading them on the boat (a 400-amp hour pack is not light BUT, it is a LOT lighter that the old AGM batteries!) I was able to carry each battery on board and down the stairs.
The next step prior to installing is that we needed to "parallel" each pack. Step 1 was to charge each pack to 100%. They were at about 30% SOC (state of charge) so we had to put about 280 amps into each "pack", one at a time. With our 60-amp charger (we have a 100-amp charger as well but it runs on 115 VAC, aka; North American voltage OR our generator. Our 60-amp charger that we bought a few years ago takes anywhere from 95 to 250 volts input and either 50 or 60 hz. So, since we could plug in to the 230 volts at the marina, we used it.) It took about 4 ½ hours for each battery. We finally finished at abut 3 AM. (we did sleep while waiting...) Sometime during the charging of the Lithium's I found time to re-program the other battery chargers including the 100 amp, the solar charges and monitor to the new Lithium settings.
The instructions then had us parallel the two battery packs under "controlled conditions" so as to NOT zap the new batteries. We had charged to within the prescribed "0.2 volt" difference in each pack's voltage and now we had to connect them together with a wire of "suitable resistance" of 0.004 Ohms to keep the paralleling from happing too quickly and causing damage to the Lithium cells. (the zapping I mentioned).
Well, I am sure we all know how to do that! After a bit of research (previously done) I knew that 4 feet of 10 AWG wire has exactly 0.004 Ohms of resistance. We connect the 2 battery packs and watched the electrons flow as they equalized. Ok, not really but each pack does have its' own battery monitor gauge and we watched and waited for them to be exactly the same voltage. It took about 30 minutes instead of being almost instantaneous if we had used a normal sized battery cable.
Now was the most difficult part of the whole job, removing the old AGM batteries. We had waited until we had everything ready and then turned off the ships power (read: fridge and freezer + other stuff) at 0800 and started. First was to remove all of the old battery cables (a bunch of them; we had 4 batteries wired together in parallel). That was easy. Then just remove the old batteries, 4 of them; not so easy. They were in a fiberglass box with the handles tuck neatly inside. Neat enough that we could not use them. The first battery was the most difficult, it took about an hour; yes, an hour, to just get it out of the box. That included attaching lines to the battery posts and then threading another line through the other side. Each of these old AGMs is 152 pounds or 69 kgs.
The second and third battery were easier but we still need to tie lines under each one to lift it. The fourth we were able to turn and use the handles to just lift (152 pounds) out.
Now we had to get 608 pounds of batteries off the boat...
Well, that morning I had bumped into Adrian on the dock. Adrian is the guy that looked after Hedonism when we were home last time for 5 months. I asked him if he wanted the batteries. He did not but he knew someone who did. How much $$$? Free, but the caveat was "you want them, you come and get them"! Within an hour the new potential battery owner showed up. I explained the "deal". We wasn't in stellar shape but was off in a flash to recruit "young guys" to carry them. Mission accomplished and my back was saved!
Once the batteries were off the boat we quickly installed and connected the new Lithium battery packs.
At precisely 1300 we turned the power back on and we were underway back to the anchorage by 1600 and very importantly, 430 pounds lighter!
So, except for putting the boat back together, the main part of that project was complete. Our new 800 amp/hour battery bank was installed and while the previous AGM batteries were 840 Amp/hours, we now have closer to 600 amps of useable energy. But; you need to feed them.
So back at the anchorage we set out to installing the 2 new 340-watt solar panels. Everything that we needed to do the install was in the Ocean Shipment with the battery packs. Or so we thought. It turned out that the Aluminum bars we were going to use to mount the new (heavier) panels on were not up to the task; as in not strong enough. Darn. Finding anything in Tahiti is usually a problem so I took the dive and ordered what I needed to finish the task from the U.S. In fact, they have just arrived in Tahiti yesterday so we will be heading back to Tahiti on Monday morning to pick them up and finish that job. This of course is why we are still here!
I will say though, we love the new batteries. You do not have to have to monitor the voltage like a normal battery as it will not tell you the battery state. The voltage on Lithium's stays virtually constant so observing the voltage in fact, will not well you the state of the battery, you must measure the amps; in and out. There is a meter on each pack that tells us the SOC. (state of charge). The refrigeration on the boat is now running more efficiently at the higher constant voltage as is everything else. We have a new battery monitor in the shipment that is coming. While it does give you voltage, it also measures those amps like a fuel gauge and can give us the SOC at a glance.
The only negative thing about these lithium batteries is that you cannot charge them below 0 c or freezing. We won't need to worry about that for a long time, if ever!